The present invention relates to a system for the control of a wheel for driving in rotation a chronograph hand, comprising a lever for returning the hand to zero and the associated wheel, a rocker for coupling the hand wheel to an intermediate wheel and a column wheel for the control of the said lever and the said rocker.
The known chronograph control systems suffer from the drawback that they are not adapted to prevent a lateral shock or vibrations from causing the rotation of the hand when the latter is at a stop and in a position other than its returned-to-zero position. Now the angular position of the hand represents an information which, therefore, may be lost as a result of such a shock or vibrations.